New tech boosts the 5G experience with greater spectral efficiency
Spectral pooling combines TDD and FDD spectrum by combining proprietary Huawei algorithms with industry-standardised technologies. Credit: DANIEL CONSTANTE via Shutterstock. ·Verdict·DANIEL CONSTANTE via Shutterstock.
GlobalData Technology
5 min read
Mobile operators around the world continually face a key challenge in spectral efficiency.
The data traffic volumes in their networks keep rising as users demand more from their mobile devices, placing increasing burdens on the network.
However in some ways, these networks are limited in their ability to keep up with user demand. One of the key limitations on network capacity is the spectrum that data travels through wirelessly from the cell tower to the user device.
In most cases, mobile operators have paid dearly for the right to access this licensed spectrum, and they need to monetise their investments in spectral assets as much as possible.
Managing spectrum use
It’s extremely important for operators to manage their spectrum utilisation in the most efficient way possible. However this is no easy task, since the network, and its spectrum, have become increasingly complex in multiple ways.
Most operators with 5G networks are still simultaneously operating 4G networks as well. They’re also using multiple different frequency bands, some of which have less bandwidth but more coverage and some of which have less coverage but more bandwidth. In addition, modern networks intelligently focus beams at specific users, which increases complexity further, as operators have an increasing number of beams to manage and optimise to give users the best experience.
Fortunately for those operators, the equipment vendors that supply their network infrastructure have worked to address these challenges with an array of new technologies, including software features, aimed at increasing efficiency.
Dynamic spectrum sharing and spectral efficiency
For years, operators have used Dynamic spectrum sharing (DSS) to manage 4G and 5G efficiently by letting the two technologies occupy the same wireless spectrum frequencies. However a recent evolution of this technology from Huawei Technologies – which supplies mobile base station equipment and software, among other things -- takes it a step further.
A new evolution of spectrum sharing from Huawei called GigaBand allows all of a mobile base station’s spectrum to be used for 5G when 4G traffic volumes are low. This not only increases spectral efficiency but aids in the evolution toward fully 5G networks.
GigaBand uses another technology, called Multiband Serving Cell (MBSC), to increase efficiency by focusing on the network’s control plane. The traffic that flows through the network contains a data plane – the content of the communications being sent – and the control plane, which tells the network where and how to send that data. MBSC helps make that control traffic more efficient by squeezing multiple network control transmissions into a single channel, freeing up spectral resources by packing more signal into less spectrum “space.”
GigaBand also uses spectrum pooling, which maximises spectral efficiency by intelligently combining two kinds of spectrum: time-division duplex (TDD) spectrum – which is typically used for enhancing capacity in mid-band spectrum – and frequency-division duplex (FDD) spectrum, which is often used for extending coverage using low-band spectrum.
Spectral pooling
Managing these two spectrum types efficiently is an ongoing challenge for operators. Spectral pooling combines TDD and FDD spectrum by combining proprietary Huawei algorithms with industry-standardised technologies, such as single downlink control information, or DCI, which allows scheduling of multiple shared downlink channels. The result combines the benefits of FDD spectrum’s coverage and TDD spectrum’s bandwidth in an efficient way.
Huawei’s GigaBand offering combines spectrum pooling with the pooling of other network resources, including transmission power. Additionally, its GigaGear feature converges 4G and 5G to improve network efficiency during the migration to 5G.
Another technology tasked with increasing network efficiency does so by making the network faster and more widely orchestrated. Huawei’s eMIMO Pro (whose acronym refers to the Multiple-Input/Multiple-Output technique used by wireless networks to send and receive information) solution improves spectral efficiency by aiding a common process in mobile networks called “scheduling.”
Scheduling is how each piece of data in a network transmission is assigned a dedicated spot on the spectrum at a specific time. When scheduling errors occur (because the network is too congested, for example), some data may be lost, degrading the user experience. Huawei’s eMIMO Pro offering improves scheduling in two ways: It allows scheduling to be performed faster and it coordinates scheduling of different transmissions, staggering them in relation to each other in order to cut down on interference between them.
Getting on beam
New technologies are also enhancing Massive MIMO, the radios with large integrated antenna arrays that are essential for 5G because they use beamforming – the cell site’s targeting of specific users. Smart Massive MIMO can recognise various scenarios and automatically configure more than 300 parameters to optimise network performance for the present scenario – for example, by adjusting beam width and power.
There are other ways to improve beamforming. Huawei’s iBeam – offering does it in two ways: (1) it predicts where users will move next so that beams can target them more accurately as they move and (2) it tracks spectrum channels more frequently -- in 1-millisecond increments. iBeam does this using Sounding Reference Signals (SRS), which are typically used to test reception quality for uplink traffic management. The feature uses SRS information to reduce signal interference and also to aid scheduling – using predictions about where users will move next to anticipate the ideal spectral resources to meet their needs as they move, thus improving the network connection and in turn the user experience.
These are a few examples of technologies unveiled recently to advance the efficiency of mobile networks. Going forward, equipment vendors are also investigating the potential to gain even greater network efficiency using artificial intelligence, though research on this subject is currently at a relatively early stage.
Mobile operators will always seek to get the most out of their spectral assets. And as they look to new generations of mobile technology, including 6G, they will look for new spectrum bands to employ. However in the meantime, they can explore a range of new technologies to maximise the return on the spectrum they already have.
"New tech boosts the 5G experience with greater spectral efficiency" was originally created and published by Verdict, a GlobalData owned brand.
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